Abstract

We demonstrate that remote plasma hydrogenation can increase electron concentrations in ZnOsingle crystals by more than an order of magnitude. We investigated the effects of this treatment on Hall concentration and mobility as well as on the bound exciton emission peak for a variety of ZnO single crystals–bulk air annealed, Li doped, and epitaxially grown on sapphire. Hydrogen increases intensity in conducting samples annealed at 500 and 600 °C and partially restores emission in the range for Li-diffused ZnO. Hydrogenation increases carrier concentration significantly for the semi-insulating Li doped and epitaxial thin film samples. These results indicate a strong link between the incorporation of hydrogen, increased donor-bound exciton PL emission, and increased -type conductivity.